1. Field of the Invention
The present invention relates to electrophotographic copying machines which employ and consume xerographic toner powders or developers for the development of electrostatic images during the production of copies of imaged originals.
More particularly, the present invention relates to improved assemblies for the attachment and periodic replacement of filled toner containers to the housing of a toner cartridge comprising a compartment from which toner is metered to the image-development station of an electrophotographic copying machine.
2. State of the Art
In known electrophotographic machines having refillable toner compartments designed to be refilled or replenished by the user pouring toner thereinto from a toner container, there is substantial risk of toner spillage and waste, and of contamination of the machine, the work environment and the user.
Reference is made to U.S. Pat. No. 5,383,502 for its disclosure of a toner-supply container having a lid which is automatically opened to dispense toner into a toner-metering compartment of a copying machine when the toner container lid is moved into engagement with an unlatching mechanism, providing clean and automatic toner replenishment.
Reference is also made to U.S. Pat. Nos. 5,797,073 and 5,852,760 which disclose motor-driven toner containers for metering toner particles to the developer unit of an electrophotographic copying machine. Both of these patents disclose rotatable toner-supply containers which interlock with the toner storage unit of the machine and have an aperture from which toner is metered with each horizontal rotation of the supply containers.
The toner-supply containers of U.S. Pat. No. 5,797,073 incorporate a sealing means for the toner-release aperture, which sealing means is normally biased to seal the aperture when the container is separated from the apparatus, to prevent spillage of the toner before and during the connection of the toner supply container to the apparatus. Rotation of the container, during operation of the copy apparatus, causes the sealing means to be opened to permit metering of the toner composition into the toner storage compartment.
It is desirable to avoid the need for mechanically rotating the toner-supply container and therefore the modern electrostatographic machines incorporate vertically-supported toner-supply containers which feed toner composition into the toner-storage compartment of the apparatus by gravity flow. It is also necessary to preclude the premature release or spillage of the toner composition from such containers during attachment and/or detachment of the containers in vertical orientation from the apparatus.